Class 127 Derby 4-car DMUs

Thirty of these sets were built, each formed of 2xDMBS, TS and TSL. They were high density sets
with no gangway connections, with seats for 352 2nd class passengers, later reduced to 348.
Rarely venturing from the intensively worked St. Pancras to Bedford line, this earned them the
name Bed-Pan units.

Built with a blue square control system problems with driver errors when coupled to gearbox
units meant the vehicles were reclassified as red triangle units.

They lasted in passenger service on the line until electrification in '83 when the power cars
were withdrawn, although a good few went into parcels use. A lot of trailers were transferred
to Tysley and lasted another ten years.